code: def batch_fn(self, batch_nodes):
      graph_list = neighbor_sample(
          self.dataset.graph, batch_nodes, self.samples
      )
  
      neigh_nodes = graph_list[0][1]
  
      #         x = self.dataset.x[neigh_nodes]
  
      y = self.dataset.y[batch_nodes]
      return graph_list, neigh_nodes, y
  
imports: import os
  import tqdm
  import yaml
  import pgl
  import time
  import copy
  import numpy
  import os.path
  from pgl.utils.logger import log
  from pgl.graph import Graph
  from pgl import graph_kernel
  from pgl.sampling.custom import subgraph
  from ogb.lsc import MAG240MDataset, MAG240MEvaluator
  from dataset.base_dataset import BaseDataGenerator
  import time
label_desc: Use image node_id 2 for calling the DataGenerator obj's underlying member method code with example usage: obj.batch_fn(batch_nodes) and returns: graph_list,  neigh_nodes,  y